Fabrication of graphene oxide/multi-walled carbon nanotube/urushiol formaldehyde polymer composite coatings and evaluation of their physico-mechanical properties and corrosion resistance

摘要

Multi-walled carbon nanotubes (MWCNTs) were uniformly dispersed in an urushiol formaldehyde polymer (UFP) by in-situ condensation polymerization with an alkali catalyst, and then modified graphene oxide/multiwalled carbon nanotubes/urushiol formaldehyde polymer (GO/MWCNTs/UFP) composites coatings were fabricated via solution blending. The microstructure, physico-mechanical properties and anti-corrosion properties of the GO/MWCNTs/UFP composite coating were studied. By optimizing the GO/MWCNTs content (0.5 wt.% GO/1.0 wt.% MWCNTs), a significant improvement of the alkali resistance and physico-mechanical properties was realized. The morphology of the as-prepared UFP composite films was studied using scanning electron microscopy (SEM). The SEM demonstrated that the MWCNTs were well dissolved and covered by the GO. The hardness, adhesion, surface drying time and corrosion resistance of the GO/MWCNTs/UFP composite coating were obviously improved compared to the pure UFP, with a relatively fast surface drying time of 30 min. The hardness and the adhesion grade of the GO/MWCNTs/UFP composite coating (0.5 wt.% GO/1.0 wt.% MWCNTs) reached the highest level of 6H and 1, respectively. When a tinplate was coated with the GO/MWCNTs/UFP composite, the corrosion rate decreased to 1.62 x 10(-5) mm/a, and the protection efficiency increased to 99.70%. The resulting GO/MWCNTs/UFP films exhibit outstanding properties in terms of electrochemical corrosion, alkali-resistance, hardness and adhesion, which indicates their high potential for use in applications on offshore steel structures.